Resistance device



y 2, 1929- H. T. HAYDEN. JR 1.719.179

RESISTANCE DEVICE Filed July 19, 1926 2 Sheets-Sheet 1 ooooooooocaawoentoz flzzry Zflaydmfi 351 W (lame/1 4 A W mg-v 6M y H. T..HAYDEN. JR1.719.179

RESISTANCE DEVICE Filed July 19, 1926 2 Sheet s-Sheet 2 o I v o 44 @194i 4.5 @5 Q/zz s K x 9 TH mkhe ,5 2 Z3-- m7 y s 2 a'vweutoz 1/6/2131THql/dm J! 93 4M abto'mwlp Patented July 2, l92 9.,.

UNITED STATES PATENT OFFICE.

HENRY T. HAYDEN, JR, OF NEW YORK, H. Y., ASSIGNOR T0 WARD LEOITABDELECTRIC COMPANY, A CORPORATION OF .NEW YORK.

nnsrsrmcn DEVICE. f

Application filed my 19,

This invention relates to electric resistors of the sheet metal type andto the method of constructing the same.

The principal'objects of my invention are to provide a resistor of thischaracter hav ing a continuous resistance element or conductor ofimproved form, and to provide an improved method of constructing suchresistor wherein the continuous resistance element is formed from asingle sheet of metal'with'little or no waste of material.

' Further objects are to provide an improved resistor which is simple,light, strong and durable in construction, economical in cost ofconstruction and eflicient in operation. Such a resistor may consist ofa single suitably mounted resistance element or may comprise a pluralityof such elements, each of which, with its mounting, forms a separateresistance unit of the resistor, and a further object of my invention isto provide an improved resistor comprising a plurality of such units.

Other objects of my, invention will appear from the followingdescriptiontaken in connection with the accompanying drawing,.wherein Fig; 1 showsa sheet metal blank from which a resistance element, employed in oneform of my resistor, is made.

Fig. 2. is a side elevation, partly in section, of a resistor orresistor unit emplding a resistance element formed from t e blank shownin Fig. 1.

Fig. 3 is asectional view taken on the line 3-3 of Fig. 2.

Fig. 4 is a view similar to Fig. 2, but showing a resistor having aresistance element of somewhat modified form.

Fig. 5 is a view'similar to Fig. 1, but showing a modified form of sheetmetal resistance" element blank.

Fig. 6 is aside elevation of a modified resistor or resistor unitemploying a resistance element formed from the blank shown in Fig. 5.

Fig. 7 is a partly diagrammatic top plan view of aresistor employing aplurality of the resistor units such as is shown in Figs. 2, 4 or 6. g Y

The blank shown in' Fig. 1 is formed of a flat sheet of resistance metalin which has been formed a series of-parallel staggered slits 11,extending inwardly from opposite edges of the sheet and over-lapping oneanm. Serial 110. 123,291.

the slits 11 and the free ends of the end.

strips have terminal ortions 17 formed with openings 15, whic arelocated inline with the outer edges of the end strips. The blank of theform shown in Fig. 1 may be readily made from a flat sheet of metal bystamping and cutting.

Referring to Fig. 2, 20 represents a zigzag resistance clement formedfrom the blank shown in Fig. 1. To form the resistance element 20 eachof the connecting portions 14 are turned so that they lie parallel withone another and the axes of all of the openings which lie along eachedge of the blank are in alignment. Thus, the connecting portions 14along the bottom of the sheet and theterminal portions 17 may be given aturn of 90 in a clockwise direction when viewed from the bottom of thesheet as shown in Fig. 1, and each of the connecting portions 14 at thetop of the sheet may be given a turnof 90 in a counter clockwisedirection when viewed from the bottom of the sheet. The result vofturning the connecting portions and the terminal portions in this manneris to twist each of the strips 12 to 180 as is indicated in Fig. 2.

The resistance element 20 when formed as above described, is mounted ontwo parallel metal rods 22'and 23, which extend respectively through theupper row of openings 15 and through the lower row of openings 15 in theresistance element 20, and are securedat their ends to supportingchannel bars 21. The successive connecting portions 14 of each row arespaced from one another and form the supporting rods by insulatingsleeves 24, each of which is formed with a boss 26 which extends throughthe opening 15 into a recess or seat 27 formed in the adjacent sleeve.Each row or series of 1nsulating sleeves and spaced" connecting portions14 is firmly held on the supporting red by nuts or screw threadedwashers 30,

which are. mounted on screw threaded portions 34 of the rods and bearagainst the end sleeves of the rows. Term inal clamps 35 In Fig. 4 Ihave shown'a resistor having a somewhat modified resistance element 44,wherein each of the connecting strips 45 is formed with a longitudinalstrengthening rib 46, and each of the strips are twisted through 90 atpoints beyond the ends of the ribs instead of being, twisted throughoutthe length of the strip as in the form of resistance element shown inFig. 2. The resistance element 46 is made from blank of similar form tothat shown in Fig. 1, except that the blank has the ribs 46 stampedtherein.

In the zigzag resistance elements shown in Figs. 2 and 4, successivestrips are oppositely and'equally inclined to the vertical. In the formof myv invention shown in Fig. 6, alternate strips 50 are vertical andthe remaining strips 51 are inclined to the vertical. It will be notedthat in this form of resistor the distance between openings 15 at theopposite ends of a vertical strip 50 is somewhat less than the distancebetween the openings at the opposite ends of an inclined strip 51. Toprovlde for this difi'erence in the lengths of the strips as measuredfrom the opening at one end to the opening at the other end, and also toinsure the alignment of the openings at the lower .ends of the stripsand the alignment of the openings at the upper ends of the strips, whenthe resistor is bent into the form shown in Fig. 6, I employ a blankshown in Fig. 5 in which the openings along each side of the sheet arelocated on a line which'is inclined'to the normal of the slits 11. Theslits 11 termlnate in the sheet at points which lie on lines parallel tothe lines joining the centers of the openings 15 and the side edges ofthe blank are preferably stepped. as shown at 55 so that the connectingportions 56 which ]0lIl the ends of the strips will have square edges.If desired however, the corners of the connecting portions may befounded. The resistor shown in Fig. 5 is somewhat more compact than thatshown in Fig. 2.

In Fig. 7, I have shown the manner in which a plurality of resistorssuch as that shown in Fig. 2 or 5may be employed as resistance units toform a resistor of large! capacity. For connecting the several unitstogether, I provide rods 60 which extend through openings 61 shown inFigs. 2 and 6, located in the sides of the channel bars 21 other whenheated to high temperatures by the electric current passingtherethrough. This construction of the conducting strips eliminatesshort circuiting of the resistance element at high temperature.

I claim 1. The method of forming a resistor having a resistance elementformed from a sheet of metal, having slits therein which divide thesheet into a series of strips and two rows of substantially flatconnecting portions at the ends of the strips, the connecting portionsat opposite ends of a strip respectively joining said strip to strips atopposite sides of said strip, which method conslsts in twisting thestrips in such amanner that the connecting portions lie in parallelplanes with the connecting portions of each row, spaced from one anotherand in aligmnent, and so.- curing said connecting portions so spaced totwoparallel supports. 7

2. The method of forming a resistor having a resistance element formedfrom a sheet of metal having slits therein which divide the sheet into aseries of strips and two rows of connecting portions at the outer endsof the strips, the connecting portions at opposite ends of a striprespectively joining said strip to strips at opposite sides of saidstrip which method consists in twisting the strips in such a manner thatthe connecting portions of each row are spaced from one another in adirection normal to their faces, and all the connectingportions of eachrow are in alignment, and in mounting the said resistance element on asupport which mainsite ends of a strip respectivelyjoiningsaid strip tostrips at opposlte sides of said strip, which method consists intwisting each of the strips through a half turn so that the connectingportions of each row are spaced from one another in a direction normalto their faces, and all the connecting portions of each row are inalignment, and in mounting the said resistance element so formed on sitesides ofa strip respectively joining thesaid strip to strips at oppositesides of said strip and each of the connecting portions having anopening therethrough, which method consists in twisting the strips sothat the connecting portions of each row are spaced from one another andthe axes of t eir openings are in alignment, and in mounting saidresistance element so formed on two parallel rods extendingthro'ugh.;said

openings.

5. The method of forming a resistor having a resistance element formedfrom a sheet of metal having slits therein, which divide the sheet intoa series of strips and two rows of connecting portions at the outer endsof strips, the connecting portions at opposite sides of astriprespectively joining the said strip to strips at opposite sides of saidstrip and each of the connecting portions having an opening therethroughin line with the slits which consists in twisting each of the stripsthrough a half turn so that the connecting portions of each row arespaced from one another and the axes of their openings are in alignment,and in mounting said resistance element so formed on two parallel rodsextending through said openings.

6. The method of forming a resistor having ,a resistance element formedfrom a sheet of metal having slits therein which divide the.

sheet into a series of strips and two rows of connecting portions at theouterends of the strips, the connecting portions at opposite ends of astrip respectively joining the said strip to strips at opposite sides ofsaid strip, which method consists in twisting the strips a half turn andsupporting the con.-

7. The method of forming a resistor having a resistance element formedfrom a sheet of metal having slits therein which divide the sheet into aseries of strips and two rows of connecting portions at the outer endsof the strips, the connecting portions at opposite ends'of a striprespectively joining the said strip to strips at opposite sides of saidstrip, which method consists in twisting the strips substantiallythroughout the length of the strips and bringing each of the connectingportions in planes parallel to each other, andv supporting each of theconnecting portions at therespective ends of the strips in alignment. A

8. .A continuous resistance element of slitted sheet metal, said elementhaving a zigzag form and comprising strips and connecting portions atthe outer ends of the strips, the connecting portions along each side ofthe element being fiat and facing one another in alignment and thestrips being twisted.

9. A resistor comprising a continuous resistance element of slittedsheet metal, said element having a zigzag form and comprising strips andconnecting portions at the outer ends .of the strips, each of saidconnecting portions having an opening therein in line with the slits,the metal of said strips being twisted so that the connecting portionsalong each end of the strips face one another and are spaced fromone'another and the axes of their openings are in alignment, andsupporting means extending through said openings.

10. A resistor comprising a continuous resistance element of slittedsheet metal, said element having a zigzag form and comprising strips andconnecting portions at the outer ends of the strips, each of saidconnecting portions having an opening therein, said strips being twisted.so that the connecting portions along each edge of the element arespaced from one another and the axes of their openings are in alignment,an insulated supporting rod extending through the open"- ings at oneedge of said element and a second insulated supporting rod, parallel to'said first named rod, extending through the openings at the other edgeof said element.

HENRY T. HAYDEN, J R.

